Described is an apparatus that comprises: a first sequential unit; a first queue coupled in parallel to the first sequential unit such that the first queue and first sequential unit receive a first input, the first sequential for double sampling the first input; a compare unit to receive an output from the first sequential unit; and a first selection unit controllable by a write pointer of a previous cycle, the first selection unit to receive outputs of each storage unit of the first queue, wherein the first selection unit to generate an output for comparison by the first compare unit.